Handicapping the Apple news at today’s developers conference

FORTUNE — With the Tim Cook’s keynote address at Apple’s AAPL World Wide Developers Conference only hours away, there’s no shortage of speculation from Apple bloggers and Apple analysts about what’s in store. But only Piper Jaffray’s Gene Munster has assigned percentages to the possible announcements.

Excerpts from his Monday morning note to clients:

90% Chance of Redesigned iOS. “It will be the first time in 6 years that Apple will tweak its world class innovative interface. Overall, we believe making these changes is the right move for Apple given consumers are increasingly interested in some fresh ideas from Apple around the iOS interface. The risk of doing nothing is greater than the risk of disrupting the winning iOS formula.”

80% Chance of “iRadio” Ad Supported Music Service. “If Apple were to equal Pandora’s Street revenue estimate in CY14 of $875m, it would add about 0.5% to overall Apple revenue. More importantly, we view the music offering as an opportunity to show consumers that they can deliver new, useful services with great experiences to make up for disappointments in Mobile Me and Maps.

80% Chance of New Maps & Update To Siri. “Apple will likely takes steps to improve points of interest on maps (launched last year at WWDC) and add additional partners to Siri.”

40% Chance of New Macbook Air. “We estimate about 40% of all Mac’s are Macbook Air. Overall, the Mac business accounts for about 12% of sales and is not a long term growth business.”

20% Chance of iPhone 5S and Digital Wallet. “Tim Cook made it clear that new products start in the fall of this year, but there is an outside chance that iPhone 5S sneaks into WWDC. We believe the incremental feature will be around biometric security, which could ultimately enable the digital wallet, addressing waiting in line at retails, receipt management and loyalty programs.”

10% Chance of App Store For Apple TV. “Our confidence remains high that Apple will have an actual TV announced by year end and ship in the first part of 2014 based on comments from Tim Cook at the D11 conference two weeks ago. We think there is an outside chance that Apple introduces an App Store for the existing Apple TV, which would enable Apple to begin gathering developers ahead of the full television launch. Overall, we believe if the TV were to ship in the first part of 2014, it could add 10% to the Street’s CY14 revenue and 4% to earnings (assuming 10% of the connected TV market or 11 million units at $1,750, with a 15% gross margin).”

The keynote starts at 10 a.m. PST (1 p.m. EST). Adam Lashinsky and JP Mangalindan will be covering it for Fortune. I’ll be at the e-book antitrust trial, where the judge is starting to see things Apple’s way.

UPDATE: As several readers have mention, Apple will be streaming the keynote live from its Special Events page.